APPLE Me MODEL A2S2064
CC10
SAMS.
Remove staples and use cover for file folder.
COMPUTERFACTS™ put easy to use, informative technical data right at your fingertips. Each edition includes specific
service information on the individual component, along with some overall troubleshooting hints.
The following information is just a sample of the many valuable time saving
features contained in this exclusive Sams COMPUTERFACTS publication:
Preliminary Service Checks section is an easy to use, step by step guide for the
experienced technician or hobbyist, and even beginners.
SAMS famous industry accepted standardized notation schematics containing
CircuiTrace 8 , GridTrace™, waveforms, voltages and stage identification.
3T
• Ste p by Step Troubleshootin g guides the technician through the necessary
procedures to quickly locate the problem.
TROUBLESHOOTING
MtCSOPBOCCSSOB CHIP (CPU) OPERATION
Ve«t> Irte processor is lunclion>ng by electing ihe signals
on the address Ones ipms 10 tf»u 24 of IC UGOOl and me dala
■ 1<nes(p*ns 41 llwu 5fi| using a fogic proee or a scope if a logic
prooe "S used reler lo Ihe 'Logic Chan" for Ihe correct
readings u a scope >s jsed. me *a»etorms on me address
inesie.cepi cms 22 and 23*nicn have no signal in Po*e< Jp
model should be similar lo Figure I The waveforms on Ihe
data lines should be similar to Figure 2
• Log ic Chart containing logic probe readings to isolate defective circuitry and
components. LOGIC
PIN
IC
PIN
IC
PIN
IC
IC
IC
IC
IC
IC
IC
IC
NO.
UI0O
NO.
U100
NO.
U102
U103
Jl 04
UI05
U106
UI07
U108
UI09
1
p
21
P
1
L
L
L
L
L
L
L
L
2
p
22
P.
2
P
P
P
P
P
P
P
P
3
p
23
P
3
H
H
H
H
H
H
H
H
• Quick Component Location using the SAMS exclusive GridTrace, CircuiTrace,
and component photographs.
5 6
lv 3
7
10 n 12
• Complete Components Parts List in an easy to use format with field replacements
shown when possible. SAMS unique semiconductor, chip and IC cross-reference
gives you many replacements to choose from and is available at your Electronic
Distributor.
SEMICONDUCTORS (Select replacement for best results)
ITEM
No.
TYPE
No
MFGR
PART No
REPLACEMENT DATA
ECG
PART No
GENERAL
ELECTRIC
PART No
MOTOROLA
PART No
NTE
PART No
RCA
PART No
WORKMAN
PART No
ZENITH
PART No.
0102
1SS53
1 149-2576
ECG5I9
GE-514
IN4935
NTE519
5K9091/I77
HEP925/519
103-131
D103
1 N50 E *
1149-2527
ECG 109
1N60
NTE 109
SK3068
WEPI 34/109
10 3-Z9C0 1
D201
1N4004GP
1201-4205
ECG1 16
GE-504A
1N4004
NTE116
SK33I 2
WEP157
212-76-02
0501 thru
ISS53
1149-2576
ECG519
GE-514 ,
1N4935
NTE519
SK9091/177
WEP925/5I9
103-131
D*03
CircuiTrace ts o registered trodemork of Howard W. Sams & Co., Inc. ,
COMPUTERFACTS and GrioTrace are irademarlcs of Howard W Sams & Co., Inc.
Apple is a registered trademark of Apple Computer, Inc.
To order, or for more information see your Sams Distributor, or
telephone 800-428-SAMS.
SAMS,. Howard W. Sams & Co.
A Division of Macmillan, Inc.
4300 West 62nd Street, Indianapolis, Indiana 46268
CC10
08920
ISBN: 0-672-08920-3
Apple Me Main Logic
Rev A
Apple P/N 661-94119
(Replaced by 91 084)
See
Note
NOTE: 820-0064-A at the top middle of board is the revision
number. This is the original Apple Me board.
Apple lie
April 1986
1.2.1
Apple lie Logic Board Unenhanced
Apple P/N 661-91084
NOTE: If the 6502 has been replaced by a 65C02, the 342-01 34 by
the 342-0303, the 342-0135 by the 342-0304, and the
342-01 33 by the 342-0265, the board has been upgraded
to "Enhanced." Any other ROM configuration is NOT
acceptable.
Apple lie
April 1986
1.2.
Apple lie Logic Board Enhanced
Apple P/N 661-0283
65C02
VIDEO ROM 342-0265 _J
I EF ROM 342-0303
I CD ROM 342-0304
NOTE: If the 65C02 has been replaced by a 6502, the342-0303 by
the 342-0134, the 342-0304 by the 342-0135, and the
342-0265 by the 341-0133, the board has been down-
graded to "Unenhanced." Any other ROM configuration is
NOT acceptable.
Apple Me
October 1986
1.2.3
Apple lie Logic Board Enhanced
Apple P/N 661-0283
NOTE: This board can be identified by a) the CF ROM and
b) the 64 x 4 RAMs.
Apple lie
October 1986
1.2.4
SAMS COMPUTERFACTS
APPLE
MODEL lie
PRELIMINARY SERVICE CHECKS
HI —
— I -I
Q_ HI
Q. Q
< o
o
o
This data provides the user with a time-saving service tool
which is designed for quick isolation and repair of Com-
puter malfunctions.
Check all interconnecting cables for good connection and
correct hookup before making service checks.
Disconnect all peripherals except the Monitor from the
Computer to eliminate possible external malfunctions.
Replacement or repair of the power supply board, main
board, disk II interface board, keyboard, or connectors may
be necessary after the malfunction has been isolated.
TEST EQUIPMENT AND TOOLS
TEST EQUIPMENT TOOLS
Digital Volt/Ohm Meter
Logic Probe
Frequency Counter
Monitor
Phillips Screwdriver
Low Voltage Soldering Iron
Desoldering Tool
Contact Cleaner
REPLACEMENT PARTS AND DESCRIPTION
6
StW>
IDENT
PART NO. DESCRIPTION
DISK II INTERFACE BOARD
UA2
UA3
UB2
UC2
UC3
UD2
UD3
MAIN BOARD
CR1
F1
S1
SP1
UA11
UA12
UB1
UB2
IC, SN74LS132N
IC, Flip/Flop, 74LS174PC
IC, 74LS05PC
IC, Latch, N9334N
IC, Shift Register, SN74LS323N
IC, Timer, MC3456P
IC, PROM, 31-0127-A
LED, Power
Fuse, AC, 2.75A
Switch, Power
Speaker
IC, RC741N
IC, Timer, NE558N
IC, Tri-State Buffer, SN74LS244N
IC, Transceiver, 74LS245N
IDENT
UB5
UB8
UC1
UC4
UC5
UC10
UC12
UD1
UE1
UE4
UE5
UE8
UE10
UE12
UE14
UF4
UF5
UF6 Thru
UF13
Y1
PART NO. DESCRIPTION
IC, Decoder/Mux, 74LS138PC
IC, SN74S02N
IC, Flip/Flop, 74F109DC
IC, Microprocessor, R6502-40
IC, HD74LS10P
IC, Decoder/Demux, DM74LS154N
IC, Mux, SN74LS251NDS
IC, Program Logic Array,
HAL16R8CN '
IC, DM74LS125AN
IC, Memory Management Unit,
344-001 0-B
IC, Input/Output Unit, 344-0020-A
IC, CD-ROM, 342-0135-B
IC, EF-ROM, C19659
IC, Keyboard ROM, 342-01 32-B
IC, Decoder, AY-5-3600-PRO
IC, Video ROM 342-01 33-A
IC, Shift Register, 74166N
IC, RAM, TMS4164-15NLJ
Crystal, 14.31818MHz
CAJkAC Howard W. Sams & Co.
&tfWTw9i* 4300 West 62nd Street, P.O. Box 7092, Indianapolis, Indiana 46206 U.S.A.
The listing of any available replacement part herein does not
constitute in any case a recommendation, warranty or guaranty by
Howard W. Sams & Co., Inc., as to the quality and suitability of such
replacement part. The numbers of these parts have been compiled
Irom information furnished to Howard W. Sams & Co.. Inc., by the
manufacturers of the particular type of replacement part listed.
Reproduction or use, without express permission, of editorial or pictorial
content, in any manner, is prohibited. No patent liability is assumed with
respect to the use of the information contained herein.
© 1985 Howard W. Sams & Co., Inc.
4300 West 62nd Streei. P.O. Box 7092, Indianapolis. Indiana 46206 U.S.A.
Printed in U.S. of America 84CC14918 DATE 3-85
PRELIMINARY SERVICE CHECKS (Continued)
SERVICE CHECKS
SEE INTERCONNECTING DIAGRAM AND PHOTOS TO MATCH THE NUMBER IN THE
CIRCLES WITH THOSE IN THE FOLLOWING DATA FOR SERVICE CHECKS TO BE PER-
FORMED.
©
COMPUTER DEAD
(A) If the Power LED (CR1) is not lit, disconnect the
Power Supply from Connector J14 and check for
5.3V at pin 3, 12.5V at pin 4, - 11.9V at pin 5 and
-5.0V at pin 6 of Connector P14. If all the
voltages are missing, check AC Fuse (F1), Power
Switch (S1) and the AC Line Cord (P20).
(B) If the Power Supply operates normally, turn Off
the Computer and remove any boards plugged in-
to the seven Peripheral Slots (J1 thru J7) or the
Auxiliary Connector (JO). Turn the Computer On
and check its operation. If the Computer starts
functioning, turn the Computer Off and plug each
board back into its respective peripheral slot, one
board at a time. After each board is reinstalled,
turn On the Computer and check its operation.
Continue this process until the defective board is
found.
(C) If the Computer does not function with the
peripheral boards removed, listen for a beep when
turning On the Computer or while pressing the
CONTROL and G keys at the same time. A beep
indicates the Microprocessor IC (UC4) is working
and the problem may be in the video circuits. If a
beep is heard, refer to the "Video" section of this
Service Checks guide. If there is no beep, check
for a momentary Low logic reading, then a High
logic reading at pin 40 of IC UC4 while turning On
the Computer. If the logic reading is incorrect,
check Input/Output Unit IC (UE5) by substitution.
(D) If pin 40 of Microprocessor IC (UC4) is normal,
check for clock pulses at pin 37 of IC UC4 and pin
12 of IC UE1. If pulses are present at IC UE1 and
missing at IC UC4, check Flip/Flop IC (UC1), Pro-
gram Logic Array (UD1), and ICs UE1 and UB8 by
substitution.
(E) If the clock pulses are normal, check the
Microprocessor IC (UC4), CD-ROM IC (UE8), EF-
ROM IC (UE10) and RAM ICs (UF6 thru UF13) by
substitution.
(F) If the Computer is still inoperative, check Tri-State
Buffer IC (UB1), Transceiver IC (UB2), Memory
Management Unit IC (UE4) and Input/Output Unit
IC (UE5) by substitution.
(?) VIDEO
(A) No video display and no beep is heard when the
Computer is turned On. Refer to the "Computer
Dead" section of this Service Checks guide. If a
beep is heard, check the video cable going to the
Monitor for good connections and possible open
circuits. Also, check the Monitor by substitution.
(B) Check IC UC5, Input/Output Unit IC (UE5), Video
ROM IC (UF4) and Shift Register IC (UF5).
(3) NO VIDEO SYNC
(A) Monitor display rolls vertically and tears horizon-
tally. Check the Input/Output Unit IC (UE5) by
substitution.
(4) GRAPHICS MODE DOES NOT WORK
(A) Check Input/Output Unit IC (UE5) and Video ROM
IC (UF4) by substitution.
NO COLOR
(A) Check the frequency of the 14.31818MHz Oscil-
lator at pin 12 of IC UE1. If the Oscillator is off fre-
quency, check the 14.31818MHz Crystal (Y1) by
substitution.
(B) If the Oscillator is on frequency, check Input/Out-
put Unit IC (UE5) and IC UB8 by substitution.
©
©
KEYBOARD
(A) Keyboard is inoperative. Check the keyboard
cable and connectors for good connections.
(B) If the keyboard cable and connectors are good,
check Memory Management Unit IC (UE4), In-
put/Output Unit IC (UE5), Keyboard ROM IC (UE12)
and Decoder IC (UE14) by substitution.
(C) Wrong character appears on Monitor screen when
a key is pressed. Check Keyboard ROM IC (UE12)
and Decoder IC (UE14) by substitution.
(D) Character repeats itself when a key is pressed
momentarily or will not repeat when a key is held
down. Check Decoder IC (UE14) by substitution.
(E) A group of keys do not work. Check the keyboard
cable and Connector J17A for good connections
and check Decoder IC (UE14) by substitution.
(F) One key does not work or is erratic. Clean the key
contacts. If the key still does not work, check the
solder connections on the bad key and check the
key contact with an ohmmeter.
NO BEEP FROM SPEAKER
(A) Computer is functioning but there is no sound
from the speaker when the CONTROL and G keys
are pressed. Check the Speaker Connector (J 18)
for good connections and check the Speaker (SP1)
voice coil for a resistance of 7.6 Ohms.
(B) Check Input/Output Unit IC (UE5) by substitution.
II
PRELIMINARY SERVICE CHECKS (Continued)
(8A)
(IB
(no
PERIPHERAL
SLOTS
DISK 11 INTERFACE BOARD
DRIVE I
\ 1M3 ~|
FLIP/FLOP
20
UA2
t
UB3
UB2
UC3
UC2
SHIFT REGISTER LATCH
DRIVE 2
UD3
PROM
i
20
]
19
25
SERVICE CHECKS (Continued)
BOARDS PLUGGED INTO PERIPHERAL SLOTS DO
NOT FUNCTION
(A) Check the edge connectors on the board for dirty
contacts. Use a pencil eraser to clean the con-
tacts if dirty.
(B) Check Decoder/Mux (Multiplexer) IC (UB5),
Decoder Demux (Demultiplexer) IC (UC10) and IC
substitution.
©
JOYSTICKS OR PADDLES DO NOT FUNCTION
(A) Check Connectors J8 and J15 for good connec-
tions.
(B) Check Timer IC (UA12), Transceiver IC (UB2), De-
coder/Mux (Multiplexer) IC (UB5), Decoder/Demux
(Demultiplexer) IC (UC10), Mux (Multiplexer) IC
(UC12), Memory Management Unit IC (UE4) and IC
UB8 by substitution.
CASSETTE
(A)
Computer will not save a
Check Input/Output Unit IC (
onto tape.
) by substitution.
(B)
Computer will not load a program from tape.
Check Transceiver IC (UB2), Decoder/Mux
(Multiplexer) IC (UB5), Mux (Multiplexer) IC (UC12),
Decoder/Demux (Demultiplexer) IC (UC10),
Memory Management Unit IC (UE4) and ICs UA11
and UB8 by substitution.
(fj) DISK II INTERFACE BOARD
(A) Disk Drive operation is erratic. Check the two Disk I
Drive connectors for good connections and check
the Disk II interface board edge connector for dirty
contacts. Clean the edge connector with a pencil
eraser if dirty.
(B) Disk Drive does not turn On. Check Latch IC
(UC2), Timer IC (UD2) and ICs UA2 and UB2 by
substitution.
(C) Will not select proper Disk Drive. Check Latch IC
(UC2) and IC UA2 by substitution.
(D) Read or write problems. Check Flip/Flop IC (UA3),
Shift Register IC (UC3), PROM IC (UD3) and IC UA2
by substitution.
(E) Does not recognize the write protect signal.
Check Shift Register IC (UC3) by substitution.
INTERCONNECTING DIAGRAM
III
PRELIMINARY SERVICE CHECKS (Continued)
t
MAIN BOARD
IV
DISK II INTERFACE BOARD
V
KEYBOARD
6F
PRELIMINARY SERVICE CHECKS (Continued*
POWER SUPPLY BOARD
2.75*
(3)
PH
WIRIN6
VIEW
5.3V -11. BV
I 3/ 5
H.31818MH2
PIN 12
©^ 11
* \«>.ov
* 12. SV
f UE1 | [ UP1 | [
UC1
TR1 -5TATE BUF FER
\ UB1
1 3 5
CRYSTAL
PR06RAM FLIP/FLOP
60 LOGIC ARRAY 3 ,
♦ ♦ ♦
♦ ♦ •
POWER
JH
POWER Of
2 4 6
IB) AUX CONNECTOR
UB2
98
CR1
o
TRANSCE I VER ( 1 0B]
® ©
UBS
JI
C'c) (id) Oe)
I
so
25
25
UF4
VIDEO ROM
^ -r==j ^
MEMORY
UC4
J2
I
50
25
25
MI
J3
SHIFT
©
UF5
RE6ISTER
UF6
UF8
UF9
I
UES
2B (SB
UBS
J4
UE8
CD-ROM
DECODER/DEMUX
® @
E3
J6
UF10
UF11
UF12
UF19 I J
UE10
©
25
X
UC10
EF-ROM
UE12
UC12
UA11
KEYBOARD ROM
@©@®
MUX
□
I JIB 11
OEM
NUMERIC KEY PAD
KEYBOARD
UA12
TIMER
CAME I/O
J17A
SPEAKER
JIB
DECODER
& I Tsp K SP7
»1 |T»ljl9
'X
JI5
JO
®
JI
MODULATOR
M/A JN BOiARD
INTERCONNECTING DIAGRAM
VI
PRELIMINARY SERVICE CHECKS (Continued)
PREVENTATIVE MAINTENANCE
ENVIRONMENT
Computers perform best in a clean, cool area that is below 80 degrees Fahrenheit and free of dust and smoke particles. Ev
though home Computers are not affected by cigarette smoke as much as commercial Computers are affected, it is better v
maintain a smoke-free area around the Computer. Do not block cabinet vents of any of the Computer system- Computei
Monitor, Printer, or other power devices.
ELECTRICAL POWER
Variations in the line voltage can affect the Computer. Try to avoid these fluctuations by using an AC receptacle that is on a
power line not used by appliances or other heavy current demand devices. A power-surge protector, power-line conditioner or
non-interruptable power supply may be needed to cure the problem. Do not switch power On and Off frequently.
KEYBOARD
Liquids spilled into the Keyboard can ruin it. Immediately after a spill occurs, disconnect the Computer power plug from AC
power outlet. Then, if circuitry or contacts are contaminated, disassemble the Keyboard and carefully rinse the Keyboard
printed circuit board with distilled water and let it dry. Use a cotton swab to clean between the keys. Use a non-abrasive con-
tact cleaner and lint-free wipers on accessible connectors and contacts.
DISK DRIVES
3
Clean the read/write heads of the Disk Drives about once a month or after 100 hours usage. Use only an approved head clean- 2 5
ing kit. O T>
r- r
Handle carefully to preserve proper disk head alignment. A sudden bump or jolt to the Disk Drives can knock the disk head out y m
of alignment. If the disk drive must be transported, place an old disk in slot and close door during transport.
Store disks in their protective covers and never touch the disk surface. Observe the disk handling precautions usually found
on the back of disk protective covers.
PRINTERS
Carefully vacuum the Printer regularly. Wipe surface areas clean using a light all-purpose cleaner. Do not oil the machine
The oil will collect abrasive grit and dust. The dust will act as a blanket. This can cause components to overheat and fail.
STATIC ELECTRICITY
Static electricity discharge can affect the Computer. In order to minimize the possibility, use anti-static mats, sprays tools
and materials, and maintain good humidity in the Computer environment.
MONITOR
Use an isolation transformer with any Monitor that does not come as part of the system since some Monitors use a HOT
chassis (chassis connected to one side of the AC line). The face of the Monitor should never be left on for long periods of time
at high brightness level except when pattern is being changed periodically. Use caution when cleaning anti-glare screens to
preserve the glare-reduction feature.
VII
PRELIMINARY SERVICE CHECKS (Continued)
GENERAL OPERATING INSTRUCTIONS
POWER UP
The Computer will come up in Basic mode when turned On
with no Disk Drive connected. If a Disk Drive is connected
the Computer will automatically boot up any bootable
diskette that is Inserted into the Disk Drive. If no diskette is
in the Disk Drive, press the CONTROL and RESET keys at
the same time to stop the Disk Drive and put the Computer
in Basic mode.
SWITCHING FROM BASIC TO MONITOR MODE
Type CALL-151 and press RETURN key. An asterisk will ap-
pear on the Monitor screen indicating the Computer is in
the Monitor mode.
SWITCHING FROM MONITOR TO BASIC MODE
Press the CONTROL and C keys at the same time, then
press the RETURN key (any Basic program already in
memory, before going to the Monitor mode, will remain in
memory).
Press the CONTROL and B keys at the same time, then
press the RETURN key (any Basic program in memory will
be lost).
RESET
Press the CONTROL and RESET keys at the same time to
reset the Computer to Basic mode. Press the OPEN APPLE
key (located on the left side of SPACE bar), CONTROL key
and RESET key at the same time to reboot the system on
any bootable diskette in the Disk Drive.
OPERATING THE DISK SYSTEM FROM BASIC MODE
(DOS3.3 OR PRODOS)
Type CATALOG and press the RETURN Key to get a list of
the programs which are on the diskette. Type CATALOG,
D1 for Disk Drive 1 or CATALOG, D2 for Disk Drive 2 if the
current disk drive is not the one desired.
Type LOAD and the program name, then press the RETURN
key to load a program from the diskette.
Type SAVE and the program name, then press the RETURN
key to save a program on the diskette.
BOOTING UP THE DISK OPERATING SYSTEM (DOS)
Insert a diskette containing a DOS into the Disk Drive 1 and
turn On the Computer. The Computer will automatically
load the DOS and come up in Basic mode if DOS3.3 is used.
If PRODOS is used the Computer will come up with menu of
PRODOS features on the Monitor screen.
To boot from Basic mode, type PR#6 or 1N#6 and press the
RETURN key. If there is no diskette in the Disk Drive, the
Disk Drive will continue to run until a diskette is inserted or
the CONTROL and RESET keys are pressed at the same
time.
DOS can also be rebooted by pressing the OPEN APPLE key
(located on left side of SPACE bar), CONTROL key and
RESET key at the same time.
USING BLANK DISKETTES
A blank diskette must be Initialized (DOS3.3) or Formatted
(PRODOS) before it can be used to save data. To initialize a
diskette using DOS3.3, boot the disk operating system from
a diskette containing DOS3.3, remove the DOS3.3 diskette
and put the blank diskette into Disk Drive 1. Type INIT
HELLO and press the RETURN key. The diskette will be in-
itialized when the drive stops. NOTE: Any previous informa-
tion on diskette will be over written and lost when initializ-
ed.
If PRODOS is being used, select the PRODOS FILER (press
F key) from the menu that comes up when PRODOS is
booted up. Select Volume Commands (press V key) from
the second menu that comes up and then select Format A
Volume (press F key) from the third menu that comes up. In-
sert the blank diskette into the Disk Drive and follow the in-
structions on the Monitor screen to format the diskette.
CASSETTE OPERATION
NOTE: The following procedure will not work if PRODOS is
loaded into the Computer. PRODOS does not support the
Cassette input-output ports.
Connect the microphone cable from the Cassette to the
Cassette Out Jack on the Computer.
Connect the speaker cable from the Cassette In Jack on the
Computer.
To save a Basic program put the Cassette in Record mode,
type SAVE and press the RETURN key. The program has
been saved when the second beep is heard.
To load a Basic program set the tone control to the high end
adjust the volume to just audible. Type LOAD and press the
RETURN key. Set the Cassette to the beginning of the pro-
gram and press the PLAY button on the Cassette. When se-
cond beep is heard, the program has been loaded.
DISASSEMBLY INSTRUCTIONS
CABINET REMOVAL
Remove nine screws from cabinet bottom. Lift cabinet top
and keyboard from chassis and disconnect keyboard plug.
MAIN BOARD REMOVAL
Release six plastic locking pins and remove four screws
holding main board to cabinet bottom. Disconnect speaker
plug and power supply plug from main board and remove
board from cabinet.
POWER SUPPLY BOARD REMOVAL
Remove four screws holding power supply to cabinet bot-
tom and remove from cabinet. Remove ten screws, five
from each side of power supply case for access to power
supply board.
VIII
Y SERVICE CHECKS (Continued*
PRELIMINARY SERVICE CK
POWER SUPPLY BOARD
N
P14
WIRING
VIEW
S.9V -I1.9V
I 3/ S
P20
@
J S1
^ J POWER
i. 31878MHz
PIN 12
^T 1
UE1 UDI
* 12.SV
[^11 [
UC1
PROGRAM FLIP/FLOP
L06IC ARRAY 3 ,
5
AUX CONNECTOR
! 003 I
TRI-STATE BUFFER
! ubi 1
©
TRANSCEIVER (108
I 3 5
POWER
J14
2 4 6
POWER ON
CR1
o ©
[
UBS
J1
0<0 0« Oe)
25
26
UE4
MEMORY MANAGEMENT
UNIT
UE5
n 3?
UC4
MICRC
PROCESSOR
©
@_
' UC5
J> UBS
J2
25
26
J3
2S
26
\ INPUT/OUTPUT UNIT
UES
OECOOER/OEMUX
© Q
© ©
CD-ROM
07)
25
26
J6
UE10
©
J7
J
(6A)
©
SLOTS
UC10
EF-ROM
DECODER/OEMUX
(9B)(lOB)
DISK J J INTERFACE BOARD
DRIVE 1
20
UA3
FLIP/FLOP
[
UB3
ran ,i=j.
E
UB2
SHIFT REGISTER LATCH
] [
UD3
UD2
timer"
DRIVE 2
2 20
I I
I 19
UE12
UC12
KEYBOARD ROM
g)@©@
MUX
©
UA11
□
M ®
JOYSTICK IN
J9
"□CASSETTE JN
□ CASSETTE OUT
1 J16 11
UEH
NUMERIC KEY PAD
KEYBOARD
[Sflli UA12
TIMER
GAME I/O
-J-i JM (»)
— VIDEO W
— r— ' OUTPUT
DECODER
J13
©
MODULATOR
J12
□
MAIN BOARD
INTERCONNECTING DIAGRAM
ERVICE CHECKS (Continued)
» *
PRELIMINARY SERVICE CHf
COMPUTERFACTS'
APPLE
MODEL He
SAFETY PRECAUTIONS PRELIMINARY SERVICE CHECKS
See page 30.
ENCLOSED
—
Block Diagram
Disassembly Instructions
General Operating Instructions
GridTrace Location Guide
Disk II Interface Board
Main Board
IC Pinouts & Terminal Guides . .
Line Definitions
Logic Chart
Parts List
_
21
6
6
22
24
5,32
31
. .27,28,29
.16 thru 20
Photos
Disk II Interface Board
Main Board
Power Supply Board . .
Safety Precautions
Schematics
Disk II Interface Board
Keyboard
Main Board
Power Supply
Schematic Notes
Dub
Page
15,22
.11,12,25,26
. . .13,14,23
30
Troubleshooting
4,33
2
. .2,35,36,37
3,34
30
...7thru10
CAA/aC Howard W. Sams &
4300 West 62nd Street, P.(
The listing of any available replacement part herein does not
constitute in any case a recommendation, warranty or 9 uaranty by
Howard W. Sams S Co., Inc., as to the quality and suitability of such
replacement part. The numbers of these parts have been compiled
from information furnished to Howard W. Sams 8 Co., Inc., by the
manufacturers of the particular type of replacement part listed.
Co.
). Box 7092, Indianapolis, Indiana 46206 U.S.A.
Reproduction or use, without express permission, of editorial or pictorial
content, in any manner, is prohibited. No patent liability is assumed with
respect to the use of the information contained herein.
© 1985 Howard w. Sams & Co., Inc.
4300 West 62nd Street, P.O. Bo, 7092. Indianapolis, Indiana 46206 U.S.A.
Printed in U.S. of America. 84CC14918 DATE 3-85
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GENERAL OPERATING INSTRUCTIONS
POWER UP
The Computer will come up in Basic mode when turned On
with no Disk Drive connected. If a Disk Drive is connected
the Computer will automatically boot up any bootable
diskette that is inserted into the Disk Drive. If no diskette is
in the Disk Drive, press the CONTROL and RESET keys at
the same time to stop the Disk Drive and put the Computer
in Basic mode.
SWITCHING FROM BASIC TO MONITOR MODE
Type CALL-151 and press RETURN key. An asterisk will ap-
pear on the Monitor screen indicating the Computer is in
the Monitor mode.
SWITCHING FROM MONITOR TO BASIC MODE
Press the CONTROL and C keys at the same time, then
press the RETURN key (any Basic program already in
memory, before going to the Monitor mode, will remain in
memory).
Press the CONTROL and B keys at the same time, then
press the RETURN key (any Basic program in memory will
be lost).
RESET
Press the CONTROL and RESET keys at the same time to
reset the Computer to Basic mode. Press the OPEN APPLE
key (located on the left side of SPACE bar), CONTROL key
and RESET key at the same time to reboot the system on
any bootable diskette in the Disk Drive.
OPERATING THE DISK SYSTEM FROM BASIC MODE
(DOS3.3 OR PRODOS)
Type CATALOG and press the RETURN Key to get a list of
the programs which are on the diskette. Type CATALOG,
D1 for Disk Drive 1 or CATALOG, D2 for Disk Drive 2 if the
current disk drive is not the one desired.
Type LOAD and the program name, then press the RETURN
key to load a program from the diskette.
Type SAVE and the program name, then press the RETURN
key to save a program on the diskette.
BOOTING UP THE DISK OPERATING SYSTEM (DOS)
Insert a diskette containing a DOS into the Disk Drive 1 and
turn On the Computer. The Computer will automatically
load the DOS and come up in Basic mode if DOS3.3 is used.
If PRODOS is used the Computer will come up with menu of
PRODOS features on the Monitor screen.
To boot from Basic mode, type PR#6 or 1N#6 and press the
RETURN key. If there is no diskette in the Disk Drive, the
Disk Drive will continue to run until a diskette is inserted or
the CONTROL and RESET keys are pressed at the same
time.
DOS can also be rebooted by pressing the OPEN APPLE key
(located on left side of SPACE bar), CONTROL key and
RESET key at the same time.
USING BLANK DISKETTES
A blank diskette must be Initialized (DOS3.3) or Formatted
(PRODOS) before it can be used to save data. To initialize a
diskette using DOS3.3, boot the disk operating system from
a diskette containing DOS3.3, remove the DOS3.3 diskette
and put the blank diskette into Disk Drive 1. Type INIT
HELLO and press the RETURN key. The diskette will be in-
itialized when the drive stops. NOTE: Any previous informa-
tion on diskette will be over written and lost when initializ-
ed.
If PRODOS is being used, select the PRODOS FILER (press
F key) from the menu that comes up when PRODOS is
booted up. Select Volume Commands (press V key) from
the second menu that comes up and then select Format A
Volume (press F key) from the third menu that comes up. In-
sert the blank diskette into the Disk Drive and follow the in-
structions on the Monitor screen to format the diskette.
CASSETTE OPERATION
NOTE: The following procedure will not work if PRODOS is
loaded into the Computer. PRODOS does not support the
Cassette input-output ports.
Connect the microphone cable from the Cassette to the
Cassette Out Jack on the Computer.
Connect the speaker cable from the Cassette In Jack on the
Computer.
To save a Basic program put the Cassette in Record mode,
type SAVE and press the RETURN key. The program has
been saved when the second beep is heard.
To load a Basic program set the tone control to the high end
adjust the volume to just audible. Type LOAD and press the
RETURN key. Set the Cassette to the beginning of the pro-
gram and press the PLAY button on the Cassette. When se-
cond beep is heard, the program has been loaded.
DISASSEMBLY INSTRUCTIONS
CABINET REMOVAL
Remove nine screws from cabinet bottom. Lift cabinet top
and keyboard from chassis and disconnect keyboard plug.
MAIN BOARD REMOVAL
Release six plastic locking pins and remove four screws
holding main board to cabinet bottom. Disconnect speaker
plug and power supply plug from main board and remove
board from cabinet.
POWER SUPPLY BOARD REMOVAL
Remove four screws holding power supply to cabinet bot-
tom and remove from cabinet. Remove ten screws, five
from each side of power supply case for access to power
supply board.
6
TROUBLESHOOTING
SELF TEST
The Computer has a self test that disables any peripheral
boards that are plugged into the main board and tests all
programmable memory. To run the self test hold down the
CONTROL and SOLID APPLE (located on the right side of
space bar) keys and press the RESET key. The Monitor
screen will turn white, then black, then white again, then
black again and come up with the message "KERNAL OK"
if no problems are found. An error message will be
displayed on the Monitor screen if a problem is found.
COMPUTER DEAD
NOTE: Turn Off the Computer before inserting or removing
boards from the peripheral slots.
No display on the Monitor screen when the Computer is
turned On. Check the Power LED (CR1). If LED CR1 is not
lit, disconnect the Power Supply Connector (J14) and check
for 5.0V at pin 3, 11.7V at pin 4, - 1 1.9V at pin 5 and - 5V at
pin 6 of Connector J14. If the voltages are incorrect, refer to
the "Power Supply" section of this Troubleshooting guide.
If the power supply checks normal, remove all the boards
plugged into the Auxiliary Connector Slot (JO) or the seven
Peripheral Slots (J 1 thru J7) and check the Computer opera-
tion. If the Computer starts functioning normally after
removal of peripheral boards, turn Off the Computer and
plug the boards into the peripheral slots one at a time. Re-
check the operation until the defective board is found.
If the Computer does not function with all the peripheral
boards removed from the slots, listen for a beep from the in-
ternal speaker when the Computer is turned On or when the
CONTROL and G keys are pressed at the same time. If
there is no beep, seethe "Microprocessor (CPU) Operation"
section of this Troubleshooting guide. If there is a beep,
check the cable from the Computer to the Monitor for good
connections. If the cable checks normal, refer to the
"Video Display" section of this Troubleshooting guide.
POWER SUPPLY
NOTE: Use an isolation transformer when troubleshooting
the power supply.
Check the AC Fuse (F1) and if Fuse F1 is open, check AC
Line Choke Coil (T1) for a possible short. If Coil T1 is good,
check associated components for shorts and check from
each lead of Coil T1 to the chassis for shorts. Check for a
possible shorted Driver Transistor (Q2).
If Fuse F1 is not open, apply AC power and check for
120VAC between Connector L and N. If 120VAC is missing,
check the Power Switch (S1), Coil T1 and the AC Power cord
Connector (P21). If 120VAC is present, check for 120VAC
across the AC inputs of Diode DB1. If 120VAC is missing,
check Coil T1 and Thermistor R1.
If 120VAC is present, check for 330V between the negative
and positive output of Diode DB1 and if 330V is missing,
replace Diode DB1. If 330V is present, check the waveform
at the base of the Oscillator Transistor (Q1). If Transistor
Q1 is not oscillating, check the voltages and components
associated with the Regulator Transistor (Q3), Regulator IC
(IC1), Transistor Q1 and Driver Transistor (Q2). Also check
the windings on Transformers T2 and T3 for continuity.
If the Transistor Q1 is oscillating properly, check the
voltages at pins 3, 4, 5 and 6 of Connector J14. If 5.0V at pin
3 of Connector J 14 is missing, check Diodes D7 and D8, Coil
L5 and Capacitors C13 and C14. Also check the
Transformer T2 windings between pin 11 and pin 12 and pin
13 and pin 14 of Transformer T2.
If 11.7V at pin 4 of Connector J14 is missing, check Diode
D6, Coil L6, Electrolytics C12 and C20 and winding between
pin 15 to pin 16 of Transformer T2 and check Shutdown
Transistor (Q4) and SCR SCR1.
If -5V at pin 6 of Connector J14 is missing, check Diode
D9, Coil L8, Electrolytics C15 and C22 and the winding be-
tween pin 7 and pin 8 of Transformer T2.
If the - 11.9V at pin 5 of Connector J14 is missing, check
Diode D10, Coil L7, Electrolytics C16 and C21 and the wind-
ing between pin 9 and pin 10 of Transformer T2.
MICROPROCESSOR (CPU) OPERATION
o
If the Computer is dead and the power supply is normal, ("J
check the logic reading on pin 40 of the Microprocessor _ k
(CPU) IC (UC4) when Computer is turned On. The logic q
reading will be Low for about .1 second then change to
High. It should also read Low as long as the CONTROL and
RESET keys are held down. If the logic reading is incorrect,
check Input/Output Unit IC (UE5) by substitution. 2
O >
If the reset circuit is working, check the 1MHz clock wave- m "O
form at pin 37 of IC UC4. If the waveform is missing, check PT jZ
the waveform at pin 14 of Program Logic Array IC (UD1). If jjf
the wavform is present at pin 5 of IC UB8 and pin 6 of IC UB8
logic reading is Low, check IC UB8 by substitution. If the
waveform is missing at pin 5 of IC UB8, refer to the "Crystal
Oscillator and Dividers" section of this Troubleshooting
guide.
If the clock waveform at pin 37 of IC UC4 is normal, check
for clock pulses at pins 3 and 39 of IC UC4. If the pulses are
missing, check IC UC4 by substitution. If the pulses are
present, check for a High logic reading on pins 2, 4 and 6 of
IC UC4. If any of the logic readings are Low, check the part
of Resistor Network RP1 connected to the pin with the Low
logic reading. Also check for a possible short to ground
and check IC UC4 by substitution.
To check the address li nes, turn Off the Computer , remnye '/jp£££
any peripheral boards plug ged into the main board, connect
a jumper fromj in 2 of IC UB8 to jrnnnn; turn On the Com- - M .
puter and check for a Low logic reading on pins 9 thru 20 . .
and 22 thru 25 of IC UC4. If any of the pins do not read cor- 5l*Tfc
rectly, check IC UC4 and the Tri-State Buffer ICs (UB1 or
UB3) connected to the bad pin, by substitution. If the ad-
dress lines on IC UC4 read logic Low, check the buffered ad-
dress lines, pins 3, 5, 7, 9, 12, 14, 16 and 18 of ICs UB1 or
UB3 for a logic Open (No lights On). If any of the buffered
address lines read a logic High or Low check by substitu-
tion any IC associated with the defective line.
If no problems have been found at IC UC4, check CD-ROM
IC (UE8) and EF-ROM IC (UE10), Memory Management Unit
IC (UE4) and RAM ICs (UF6 thru UF13) by substitution
fal«l CHIP 9*P H»»b& At "I cVBrtPrflt D(SPL«n
7
TROUBLESHOOTING (Continued)
CRYSTAL OSCILLATOR AND DIVIDERS
Check the oscillator frequency (14. 31818MHz) at pin 12 of IC
UE1. If the oscillator is off frequency, check 14.31818MHz
Crystal (Y1). If the oscillator is not working, check the
voltages and components associated with Output Tran-
sistor (Q4) and Oscillator Transistor (Q6).
If the oscillator is working, check the waveform at pin 11 of
IC UE1. If the waveform is missing and pin 13 of IC UE1
logic reading is Low, check IC UE1 by substitution. If the
waveform is good, at pin 1 1 of IC UE1, check for a frequency
of 3.5795MHz at pin 10 of Flip/Flop IC (UC1). If the signal is
missing or the frequency is incorrect, check IC UC1 by
substitution. If the frequency is correct at pin 10 of IC UC1,
check the waveforms at pins 14 thru 16 and 19 of Program
Logic Array IC (UD1) and pins 6 and 15 of Shift Register IC
(UF5). If any of the waveforms are missing, check IC UD1 by
substitution.
KEYBOARD
If Computer comes up properly but the keyboard is dead or
has no response when any key is pressed, check Connector
J14 and the cable from the keyboard to the main board for
good connections. If the cable and connectors are normal,
check for -11.9V at pin 27 of the Decoder IC (UE14). If
- 11.9V is missing, refer to the "Power Supply" section of
this Troubleshooting guide. If - 1 1.9V is present, check the
waveform at pin 1 of IC UE14. If the waveform is missing,
check Capacitor C70, Resistor R32 and check IC UE14 by
substitution. If the waveform is present at pin 1 of IC UE14,
check the waveforms on pins 16 thru 26 and 33 thru 40 of IC
UE14. The waveforms on pins 17 thru 26 should look similar
to the waveform shown in Figure 1 and the waveforms on
pins 33 thru 40 should look similar to Figure 2.
Figure 1
Figure 2
3.8V
50/<s
-8V
DC
Reference
.3V
50/<s
-8V
DC
Reference
If any waveform is missing, check IC UE14 by substitution.
If the waveforms are present, check the logic readings on
pins 5 and 16 of IC UE14. Pin 5 logic reading should be High
and pin 16 should read a Pulse when any key is pressed ex-
cept the CONTROL, SHIFT, CAPS LOCK, RESET and APPLE
Keys. If either reading is incorrect, check IC UE14 by
substitution. If the readings are correct, check waveform at
pin 18 of the Memory Management Unit IC (UE4). If the
waveform is missing at pin 18, check the IC UE4 by substitu-
tion. If the waveform is present at pin 18 of IC UE4, check IC
UE12 and Input/Output Unit IC (UE5) by substitution.
If only one key does not work, check the solder connection
on the defective key and check the key for continuity when
the key is pressed.
If only one key is erratic, clean the contacts of the defective
key. If a wrong character appears on the Monitor screen
when a key is pressed, check ICs UE12 and UE14 by
substitution.
If a character appears more than once on the Monitor
screen when a key is pressed momentarily, check Capacitor
C71 and check IC UE14 by substitution.
If a character does not repeat, when a key is held down,
check Capacitor C70 and check IC UE14 by substitution.
If any one group of keys do not work, check the keyboard
cable and Connector J17A and J17B for good connection
and also check IC UE14 by substitution.
VIDEO DISPLAY
No video on the Monitor screen, check the Video Output
Jack (J11) and the cable connecting the Computer to the
Monitor for good connections. If the cable and connectors
are good, check for a 2.5V pp video waveform at the base of
Mixer Transistor (Q1). If the waveform is present, check the
voltages and components associated with Transistor Q1
and Video Output Transistor (Q2). If the video portion of the
waveform is missing, horizontal and vertical sync pulses ap-
pear, check for pulses at pin 3 of IC UC5. If pulses are pres-
ent and pin 4 of IC UC5 logic reading is High, check Resistor
R7 and check IC UC5 by substitution. If pulses are missing
at pin 4 of IC UC5, check Shift Register IC (UF5), Video ROM
IC (UF4) and Input/Output Unit IC (UE5) by substitution.
If a graphics function (low resolution) or flash and inverse
video functions do not work, check ICs UE5 and UF4 by
substitution.
If the cursor is defective or there is no cursor, check EF-
ROM IC (UE10) and IC UF4 by substitution.
VIDEO SYNC
Monitor has no horizontal or vertical sync. Check the In-
put/Output Unit IC (UE5) by substitution and check
Capacitor C25 and Resistors R5 and R10.
COLOR
No color, type and run the following Basic program and
check for pulses at pins 11 and 13 of IC UB8.
1 GR: COLOR = 4: HLIN 0.39 AT 20
If pulses are missing at pin 11, check Input/Output Unit IC
(UE5) by substitution. If pulses are missing from pin 13 of
IC UB8, check Capacitor C32, Coil L3 and check the fre-
quency of 14.31818MHz Crystal (Y1) at pin 12 of IC UE1. If
Crystal Y1 is off frequency, check Crystal Y1 by substitu-
tion. If pulses are missing from pin 13 of IC UB8, check IC
UB8 by substitution.
If colors are incorrect, the above program should produce a
green horizontal bar on the Monitor screen. Check the fre-
quency of Crystal Y1 at pin 12 of IC UE1. If Crystal Y1 is off
frequency, check Crystal Y1 by substitution. If Crystal Y1 is
normal, check ICs UD1 and UE5 by substitution.
TROUBLESHOOTING (Continued)
INTERNAL SPEAKER
If there is no sound from the internal speaker, check the
Speaker (SP1). If the speaker checks normal, type and run
the following Basic progam,
1 PRINT CHRS(7): GOTO 1
Check for pulses at pin 8 of the Input/Output Unit IC (UE5).
If pulses are missing, check IC UE5 by substitution. If
pulses are present, check the voltages and components
associated with Amp Transistor (Q5).
CASSETTE
Computer will not load a program from the tape but game
paddles and switches are working normally. Check the
voltages and components associated with IC UA11 and
check Mux (Multiplexer) IC (UC12) by substitution.
Computer will not load and there are problems with the
game paddles and switches. See "Game Paddles Do Not
Function" or "Game Switches (Joysticks) Do Not Function"
sections of this Troubleshooting guide.
Computer will not save a program on tape. Check Resistors
R6 and R9 and check Input/Output Unit IC (UE5) by substitu-
tion.
PERIPHERAL SLOTS
If a board which is plugged into one of the seven Peripheral
Slots (J1 thru J7) does not work, check that peripheral slot
for damaged or dirty pins or for possible broken solder
joints. Use a pencil eraser to clean the contacts of the
board if they appear dirty.
See that the peripheral slots pins 1, 20 and 41 that may be
used to select the board, are functioning. To do this, run
the following Basic program and check for pulses at pins 1,
20 and 41 of the peripheral slots.
FOR X =
NEXT X
FOR X =
NEXT X
GOTO 1
16255 TO - 16127 STEP 16: Y = PEEK (X):
16128 TO - 14336 STEP 256: Y :
PEEK (X):
If pulses are missing at pin 1 of any peripheral slot, check
Decoder/Mux (Multiplexer) IC (UB5) by substitution. If
pulses are missing at pin 20 of any peripheral slot, check IC
UC5 by substitution. If pulses are missing at pin 41 of any
peripheral slot, check Decoder/Demux (Demultiplexer) IC
(UC10) by substitution.
GAME PADDLES DO NOT FUNCTION
Type and run the following Basic program to check the
operation of the game paddle circuits.
The program scans all four paddles and displays the paddle
number (0 thru 3) on the Monitor screen along with a
number that is read from each paddle. The number read
from each paddle should vary between and 255 as that
paddle is varied from MINIMUM to Maximum positions. If
paddles are not available, a 100K potentiometer can be used
by connecting one end of the potentiometer to 5.0V (pin 1 of
Connector J15) and the center tap to one of the paddle in-
puts (pins 6, 7, 10 and 11 of J15).
Check Connectors J8 or J15 for good connections. If none
of the paddle inputs function, check for pulses at pin 3 of
Timer IC (UA12) and pin 7 of Mux (Multiplexer) IC (UC12)
while the above program is running. If pulses are missing,
check ICs UB5 and UC10 and Memory Management Unit IC
(UE4) by substitution. If pulses are present at pins 3 of IC
UA12 and pin 7 of IC UC12, check for pulses at pins 1 and 19
of Transceiver IC (UB2) while the above program is running.
If pulses are missing at pin 1 of IC UB2, check IC UE4 by
substitution. If pulses are missing at pin 19 of IC UB2,
check IC UB8 by substitution and check Capacitors C34,
C35, C37 and C40 and Resistors R21 thru R24.
GAME SWITCHES (JOYSTICK) DO NOT FUNCTION Q
Game paddles function but game switches do not function, o
check the switch input pins, pins 2, 3 and 4 of Connector ■*
J15 and pins 1, 6 and 7 of Connector J8, for good connec- O
tions. If the connections are good, check IC UC12 by
substitution.
10 FOR Y = TO 3
20Z = PDL(Y)
30 PRINT "PADDLE"; Y, Z
40 NEXT Y
50 PRINT
60 FOR T=1 TO 500: NEXT T
70 GOTO 10
The following Basic program can be used to check the
operation of the switch input circuit.
10Z = 2
20 PRINT "SOCKET", "X"
30 FOR Y = - 16287 TO - 16285
40 X = PEEK (Y)
50 PRINT "J 15 PIN"; Z, X
60 Z = Z+ 1: NEXT Y
70 FOR T= 1 TO 500: NEXT T
80 PRINT: GOTO 10
The program repeatedly displays on the Monitor screen the
input pin number of Connector J15 being checked with a
number X associated with the pin number given. The
number X should be 127 or less if Connector J15 pin number
shown on the Monitor screen is connected to ground (pin 8
of J15) and 128 or more if the pin is connected to 5.0V (pin 1
of J 15).
CHECKING GAME I/O STROBE SIGNAL
Type and run the following Basic program and check for
pulses at pin 5 of Connector J15. If pulses are missing,
check Decoder/Mux (Multiplexer) IC (UB5), Decoder/Demux
(Demultiplexer) IC (UC10), Memory Management Unit IC
(UE4) by substitution.
3
O >
a -o
m t>
<D
ST*feTuP PPOBCtrMS 1 X = PEEK (- 16320): GOTO 1
i
9
TROUBLESHOOTING (Continued)
DISK II INTERFACE BOARD
If the disk II interface board is not working, check the Disk
Drive Connectors (J1 and J2) and Edge Connector J6 for
good connections. If the Edge Connector J6 contacts ap-
pear dirty, use a pencil eraser to clean them.
If the connectors are normal, check the logic reading at pin
5 of Timer IC (UD2) while turning On the Computer. The
logic reading should be High for about .1 second then
change to Low. If the reading is incorrect, check Capacitor
C1, Resistor R4 and check IC UD2 by substitution.
If IC UD2 circuitry checks normal, turn Off the Computer.
Disconnect the Disk Drives from the disk II interface board
and plug the disk II interface board into Peripheral Slot (J6).
Turn On the Computer, press the CONTROL and RESET
keys at the same time to get the Computer into the Basic
mode. Type and run the following Basic program. All tests
made from this point should be made while the program is
running. Press the CONTROL and RESET keys at the same
time to stop the program.
DISK II INTERFACE TEST PROGRAM
10X = PEEK(-16151)
20 X = PEEK (- 16149)
30 X = PEEK (- 16148)
40 X = PEEK (-16146)
50 X = PEEK (-16145)
60 X = PEEK (-16147)
70 FOR Y = - 16153 TO
80 X = PEEK (Y)
90 NEXT Y
100 X = PEEK (-■
16160 STEP - 1
(- 14608): GOTO 20
^heck for a High logic reading at pin 9 of IC UD2. If the
logic reading is not High, check for a High logic reading at
pin 9 of Latch IC (UC2). If the logic reading is not High at IC
UC2, check IC UC2 by substitution. If the logic reading is
High at IC UC2 check for a Low logic reading at pin 6 of IC
UB2. If the logic reading is not Low at IC UB2, check IC UB2
by substitution. If the logic reading is Low at IC UB2, check
IC UD2 by substitution.
If the logic reading is High at pin 9 of IC UD2, check for 4.9V
at pin 16 of Flip/Flop IC (UA3). If 4.9V is missing, check for a
Low logic reading at pin 10 of IC UB2. If the reading is not
Low at IC UB2, check IC UB2 by substitution. If the reading
is Low at IC UB2, check Resistor R6 and R7 and Switch
Transistor (Q3).
If 4.9V is present at pin 16 of IC UA3, check for pulses at pin
20 of PROM IC (UD3). If pulses are missing, check Driver
Transistor (Q1) and Switch Transistor (Q2) and Resistors R1
and R2.
If pulses are present at pin 20 of IC UD3, check the wave-
form at pin 3 of IC UA2. If the waveform is missing, check IC
UA2 by substitution.
Check the Head Position Motor Outputs (pins 4, 5, 6 and 7 of
IC UC2) by checking for the waveform shown in Figure 3 at
pins 4, 5, 6 and 7 of IC UC2. If any of the waveforms are
incorrect, check IC UC2 by substitution.
I 0V
DC
Reference
The Disk II Interface Test Program enables Disk Drive 2, pin
6 of IC UA2 logic reading should be Low and pin 10 of IC
UC2 logic reading should be High. To enable Disk Drive 1,
change the number - 16149 in line 20 to - 16150 and run
the program. Pin 8 of IC UA2 and pin 10 of IC UC2 logic
reading should be Low with Disk Drive 1 enabled. If the
logic reading at pin 10 of IC UC2 is not Low, check IC UC2
by substitution. If the reading at pin 6 or pin 8 of IC UA2 is
not Low, check ICs UA2, UD2 and UB2 by substitution.
To check the write and read circuits, turn Off the Computer,
connect two Disk Drives to the disk II interface board and
plug the board into Peripheral Slot (J6). Type and run the
Disk II Interface Test Program. Check for pulses on pin 4 of
IC UB2 and at pins 11 and 12 of IC UC2. If pulses are
missing at pin 4 of IC UB2 and present at pin 12 of IC UC2,
check IC UB2 by substitution. If pulses are missing at pins
11 or 12 of IC UC2, check IC UC2 by substitution. If pulses
are present at pins 11 and 12 of IC UC2 and the disk II
interface board still has write problems, check A3 and
PROM IC (UB3) by substitution.
If the disk II interface board has read problems, check for
pulses at pins 10 and 1 i of IC UA3. If pulses are missing at
pins 10 or 11 of IC UA3, check IC UA3 by substitution. If
pulses are present at pins 10 and 11 of IC UA3, check for
pulses at pins 12 and 11 of IC UA2. If pulses are missing at
pin 12 of IC UA2, check IC UB2 by substitution. If pulses are
present at pin 12 and missing from pin 11 of IC UA2, check
IC UA2 by substitution. If pulses are present at pin 11 of IC
UA2, check IC UB3 and Shift Register IC (UC3) by substitu-
tion.
If the disk II interface board can not detect the Write Protect
signal, pin 11 of IC UC3, when a write protected diskette is
being used, check IC UC3 by substitution.
10
A Howard W. Sam$ NI NIIW Ph oto
MAIN BOARD
PIN 1
S PARTS LIST AND DESCRIPTION
When ordering parts, state Model, Part Number, and Description
SEMICONDUCTORS (Select replacement for best results)
MFGR.
PART No.
DISK II INTERFACE BOARD
01
02,3
UA2
UA3
UB2
UB3
UC2
UC3
UD2
UD3
2N3906
NS0U51
MPSU51
SN74LS132N
74LS1 74PC
74LS05PC
341-01 28-A
6309 P6A
N9334N
SN74LS323N
MC3456P
556
341-01 27-A
P5A
MAIN BOARD
91
02
04
05
06
UA1 1
UA12
UB1
UB2
UB3
UB5
UBS
UC1
UC4
^POyuo
2N3904
f*>S4258
MPSA13
NPS4258
2N4258
RC741N
MM741
NE558N
SN74LS244N
74LS245N
SN74LS244N
74LS138PC
SN74S02N
74F109DC
SI 09
R6502-40
6502B
CM <W>R &Uf
C-Oia. AAA. farti?A
Deficit /uvuaX
REPLACEMENT DATA
GENERAL
tLtOTRIC
PART No.
NEW-TONE
NTE
PART No.
PHILIPS
ECG
PART No.
RPA
PART No.
WORKMAN
PART No.
ZENITH
PART No.
GE-82
GE-253
GE-218
74LS132
74LS174
NTE159
NTE211
NTE189
NTE74LS132
NTE74LS174
ECG1 59
ECG211
ECG189
ECG74LS132
ECG74LS174
SK3466/159
SK3203/21 1
SK3200/189
SK74LS174
WEP62/159
WEP7 59/21 1
WEP857/189
121-29003
121-Z9056
121-C9053
HE-44 3-792
HE-443-879
74LS05
IN 1 t / s-LoUD
C^O"7 A 1 CAE
tLb/4Lb05
SK74LS05
HE-44 3-8 18
NTE978
IN 1 tL? 1 o
ECG978
ECG978
SK3689/978
SK3689/978
221-Z9152
221-Z9152
GE-123AP
NTE1 59
NTE123AP
ECG1 59
ECG123AP
SK3466/159
SK3854/123AP
WEP62/159
WEP736/123A
121-Z9003
121-Z9000A
GE-64
NTE 172
ECG1 72
SK3 156/1 72A
WEP971/172
121-Z9024
GE-82
NTE 1 59
ECG159
SK3466/159
WEP62/159
121-Z9003
NTE941M
NTE941M
NTE926
ECG941M
ECG941M
ECG926
SK3552/941M
SK35 52/94 1M
WEP933/941M
WEP933/941M
HE-442-22
HE-44 2-2 2
74LS244
74LS245
74LS244
74LS138
74LS02
NITF74I <^?44
NTE74LS245
NTE74LS244
NTE74LS138
NTE74LS02
NTE6502
NTE6502
P CO, 7 A 1 Q.OAA
ECG74LS245
ECG74LS244
ECG74LS138
ECG74LS02
ECG6502
ECG6502
o!\ /4LS244
SK74LS245
SK74LS244
SK74LS138
SK74LS02
HE-44 3- 791
HE-443-885
HE-44 3- 791
HE-44>877
HE-443-779
p2o«5 311- **M
z£<t
PARTS LIST AND DESCRIPTION (Continued)
When ordering parts, state Model, Part Number, and Description
SEMICONDUCTORS (Select replacement for best results)
ITEM
No.
UC5
UC10
UC12
UD1
UD3
UE1
UE4
UE5
TYPE
No.
HD74LS10P
DM74LS154N
SN74LS251 NDS
HAL16R8CN
74LS374N
DM74LS1 25AN
344-0010-B
344-0020-A
UE8
342-01 35-B
2365
2764
UE10
C19659
2365
2764
UE12
342-01 32-B
2716
UE14
AY-5-3600-PRO
AY3600931PR0
UF4
342-01 33-A
2732
UF5
74166N
LS166
UF6 Thru
TMS4164-15NLJ
UF13
6664
POWER SUPPLY BOARD
D1
D2,3
D4,5
D6 Thru
D8
D9
D10
D11
D12
RGP1 OA
RGP1 0J
1 N4606
RGP15B
RGP1 OB
1 N4606
RGP15B
MFGR.
PART No.
KM*.
341-0170-AC1) HM-
MUM
Ik co 3h2-«>ij6
6f 3H2.-cx3S|
342-0134-BC1) PF-CjdW
tltk CP 3H Z-e»M
PR0-050C1) m®****
DRAM
REPLACEMENT DATA
GENERAL
ELECTRIC
PART No.
74LS10
74LS374
74LS125A
74166
74LS166
GE-511
6E-51 1
GE-300
GE-511
GE-51 1
GE-300
GE-51 1
NEW-TONE
NTE
PART No.
NTE74LS10
NTE74LS251
NTE74LS374
NTE74LS125A
ECG74LS10
ECG74LS251
ECG74LS374
ECG74LS1 25A
>2
>52
NTE177
NTE552
NTE552
NTE177
NTE552
PHILIPS
ECG
PART No.
ECG74166
ECG74LS166
ECG2 164
ECG6664
ECG552
ECG552
ECG1 77
ECG552
ECG552
ECG177
ECG552
RCA
PART No.
SK74LS10
SK74LS125A
SK74166
i
SK5014
SK3318A
SK9091/177
SK5014
SK9000/552
SK9091/177
SK5014
an naaoiAj
31ddV
0LOO
WORKMAN
PART No.
WEP1 72/506
WEP 172/506
WEP1062/177
WEP1 72/506
WEP1 72/506
WEP1 062/1 77
WEP1 72/506
ZENITH
PART No.
HE-443-797
HE-443-863
HE-443-81 1
HE-44 3-892
103-287
103-287
103-131
103-287
103-287
103-131
103-287
PARTS LIST AND DESCRIPTION (Continued)
When ordering parts, state Model, Part Number, and Description
SEMICONDUCTORS (Select replacement for best results)
ITEM
No.
TYPE
No.
MFGR.
PART No.
REPLACEMENT DATA
GENERAL
ELECTRIC
PART No.
NEW-TONE
NTE
PART No.
PHILIPS
ECG
PART No.
RCA
PART No.
WORKMAN
PART No.
ZENITH
PART No.
DBl
IC1
01
02
03,4
KBP08
T18231
2SD467B
GEBR-1000
GE-243*
NTE170
NTE85
ECG1 70
ECG85
SK3649/170
SK3449/297
WEP1 056/1 70
WEP59/128*
212-Z9002
121-792*
2SB621R
GE-48
NTE294
ECG294
SK384 1/294
WEP916/294
121-Z9067
SCR1
Z1
2N6395
A211
2N6395
GEZD-1 1
NTE5552
NTE5020A
ECG5552
ECG5020A
SK3574
SK1 1 A/5020A
WEP1 421/5020
103-279-20
(1 ) Number on unit.
WIRING DATA
Shielded Hook-up Wire Use BEL0EN No. 8401 or 8421 (Single-Conductor)
8208 (Two-Conductor)
General-use Unshielded Hook-up Wire Use BELDEN No. 8529 (Solid) Available in 13 Colors
8522 (Stranded) Available in 13 Colors
PARTS LIST AND DESCRIPTION (Continued)
When ordering parts, state Model, Part Number, and Description
CAPACITORS Item numbers not listed are normally available at local distributors.
ITEM
No.
RATING
MFGR.
PART No.
MAIN E
C70
OARD
47 N470 50V 5%
ITEM
No.
P ATINO
MFGR.
PART No.
POWEF
CI
C3
C4
SUPPLY BOARD
.1 125VAC
.0022 400VAC
.0022 400VAC
L
RESISTORS (Power and Special)
ITEM
No.
RATING
REPLACEMENT DATA
MFGR.
PART No.
NEW-TONE
PART No.
WORKMAN
PART No.
MAIN BOARD
RP1
RP2
RP3
Res I stor Network ( 1 )
Resistor Network (2)
Resistor Network (1)
111-0017 (3)
CRL-HC31 10102M
(3)
111-0017 (3)
POWER SUPPLY BOARD
R1
R23
R24
VDR1
NTC 5 Cold
2700 2% 1/4W Metal Film
2700 2% 1/4W Metal Film
VDR
TNRG471 K (1)
QW227
QW227
22-2246
22-2246
O >
p 5
CD
(1 ) Number on un It.
COILS (RF-IF)
ITEM
No.
FUNCTION
MFGR.
PART No.
MAIN
30ARD
L1
RF Choke
L2
RF Choke
L3
RF Choke
L4
RF Choke
L5
RF Choke
L6
RF Choke
ITEM
No.
POWER SUPPLY BOARD
LI
L2
L3
L4
L5
L6
L7
L8
L99
T1
FUNCTION
RF Choke
RF Choke
RF Choke
RF Choke
RF Choke
RF Choke
RF Choke
RF Choke
Line Choke
AC Line Choke
MFGR.
PART No.
19
PARTS LIST AND DESCRIPTION (Continued)
When ordering parts, state Model, Part Number, and Description
TRANSFORMERS
ITEM
No.
FUNCTION
REPLACEMENT DATA
MFGR.
PART No.
OTHER
IDENTIFICATION
POWER SU
T2
T3
PPLY BOARD
Switching Power
Switching Driver
SPEAKER
ITEM
TYPE
REPLACEMENT DATA
No.
MFGR.
QUAM
NOTES
PART No.
i
PART No.
SP1
2 1/4" PM, 8 Ohms
FUSE DEVICES
ITEM
NO.
DESCRIPTION
MFGR.
PART NO.
NOTES
DEVICE
HOLDER
F1
2.75A e 125V
Fast-Acting
MISCELLANEOUS
ITEM
No.
1 PART NAME
MFGR.
PART No.
NOTES
KEYBC
PL1
SI
thru
S63
MAIN i
cm
CR2
YI
POWEF
SI j
ARD
Lamp
Switch
OARD
LED
LED
Crystal
1 SUPPLY BOARD
Switch
Power
Part of Keyboard
Power, Red (1.8V 6 10mA)
Audio Test, Red (1.8V 6 10mA)
14.31818MHz
Power
CABINET & CABINET PARTS (When ordering specify model, chassis & color)
20
KEYBOARD
DECODER
KEYBOARD
ROM
PROGRAMMABLE
CLOCK
L06IC
ARRAY
CONTROL
LINES
J9
CASSETTE
DATA IN
MUX
JB
JOYSTICK
TIMER
SHIFT
REG
MICROPROCESSOR
TRI-STATE
BUFFERS
INPUT/OUTPUT
UNIT
VIDEO
CONTROL
LINES
B D*TA
ROMS
J
ADD
MEMORY I R ADD.
MANAGEMENT
UNIT
TRI-STATE
FLIP/FLOP
VIDEO
DATA
VIDEO
VIDEO OUT
DECODER/
DEMUX
DEV
_ADO_
DECODER/
i
iosa
RAMS
SHIFT
RE6
J11
VIDEO OUT
TRANSCEIVER
DATA
PERIPHERALS
PROM
CONTROL
READ DATA
FLIP/FLOP
WRITE DATA
PROM ADO
LATCH
0A-D
J1
TO DISK
DRIVE 1
32
TO DISK
DRIVE 2
ail 130OW
31ddV
MAIN BOARD GridTrace LOCATION GUIDE
CI
C2
C3
C4
C5
C6
C7
C8
C9
CIO
C11
C12
CI 3
C15
CI 6
C17
CI 8
C19
C20
C21
C22
C23
C24
C25
C26
C27
C28
C29
C30
C31
C32
C33
C34
C35
C36
C37
C38
C39
C40
C41
C42
C43
C44
C45
C46
C47
C48
C49
C50
C51
C52
C53
C54
C55
C56
C57
C58
C59
C60
C61
C62
C63
C64
C65
C66
C67
C68
C69
C70
C71
C72
C73
C74
C75
A-3
A-3
A-4
A-5
A-6
A-8
A-9
A-14
A-1
A-1
A-1 1
A-1
A-2
A-1
A-2
A-1
A-2
A-3
A-4
A-5
A-6
A-7
A-8
A-1 3
A-3
A-4
A-5
A-6
A-7
A-8
A-1 3
A-1 1
A-14
A-1 5
A-1 3
A-1 3
A-1 1
A-1 2
A-14
A-3
A-4
A-4
A-5
A-6
A-8
A-9
B-1
B-2
B-3
B-5
B-7
8-2
C-6
C-1
C-4
C-5
C-10
C-1 2
D-12
D-1
D-3
E-1
E-4
E-5
E-8
E-10
E-1 2
E-1 4
E-1 4
E-1 4
E-1 4
F-6
F-8
F-10
C76
F-12
R27
C-10
C78
F-2
R28
E-1
C79
F-14
R29
E-1
C80
F-14
R30
E-1
C81
F-3
R32
F-13
C82
F-3
R34
F-2
C83
F-2
R35
F-2
C84
F-4
R36
F-2
C85
F-5
R37
F-3
C86
F-7
R38
F-2
C87
F-9
R39
F-14
C88
F-11
R40
F-14
C89
F-13
R41
A-2
C90
A-2
R42
A-2
C91
A-2
R43
A-1
C92
A-1
R44
A-1
C93
A-1
R45
A-1 2
CR1
A-2
R73
F-7
CR2
A-14
RP1
C-5
CR4
F-14
RP2
C-1 1
JO
D-2
RP3
F-4
J1
A-2
UA11
A-1 1
J2
A-4
UA12
A-1 2
J3
A-4
RBI
B-1
J4
A-5
UB2
B-2
J5
A-6
UB3
B-3
J6
A-8
UB5
B-5
J7
A-9
UB8
B-8
J8
A-9
UC1
C-1
J9
A-1 1
UC4
B-4
J10
A-1 1
UC5
C-5
J11
A-1 3
UC10
C-10
J13
A-14
UC12
C-1 2
J14
A-1
UD1
D-1
J15
A-14
UD3
D-3
J16
B-1 3
UE1
E-1
J17A
B-1 4
UE4
D-4
J18
F-14
UE5
D-6
J19
B-1 4
UE8
D-8
L1
A-1
UE10
D-10
L2
A-1
UE12
E-12
L3
A-1 3
UE14
D-1 4
L4
A-1
UF4
F-4
L5
A-1
UF5
F-5
L6
A-1
UF6
F-6
01
A-14
UF7
F-7
92
A-14
UF8
F-8
04
F-2
UF9
F-9
05
F-14
UF10
F-10
06
F-2
UF11
F-11
R1
A-1
UF12
F-12
R3
A-1 2
UF13
F-13
R4
A-1 1
XI
B-1 3
R5
A-1 2
X2
B-1 3
R6
A-1 1
X3
B-1 4
R7
A-1 2
X4
B-1 4
R8
A-1 3
X5
B-1 5
R9
A-1 1
X6
B-1 4
RIO
A-1 3
X7
B-9
R11
A-1 3
Y1
F-2
R12
A-1 1
R13
A-1 3
R14
A-1 1
R15
A-1 2
R16
A-1
R17
A-14
R18
A-1 1
R19
A-14
Kz U
A-1 1
R21
A-1 3
R22
A-1 3
R23
A-1 3
R24
A-13
R25
C-2
24
MAIN BOARD
25
MAIN BOARD
26
LOGIC CHART
MAIN BOARD LOGIC
PIN
IC
IC
IC
IC
IC
IC
IC
IC
PIN
IC
PIN
IC
PIN
IC
NO.
UA11
UA12
UB1
UB2
UB3
UB5
UB8
UC1
NO.
UC4
NO.
UC4
NO.
UC5
1
P
H
L
L
L
P
L
H
1
L
21
L
1
P
2
L
#
P
P
p
P
H
H
2
H
22
L
2
p
3
L
H
P
P
P
P
L
L
3
P
23
L
3
P
4
P
H
P
P
P
P
P
P
4
H
24
P
4
H
5
P
H
P
P
p
p
p
H
5
*
25
p
5
H
6
P
H
P
P
p
P
L
P
6
H
26
p
6
p
7
H
*
P
P
P
H
L
P
7
P
27
P
7
L
8
#
H
P
P
L
L
P
L
8
H
28
P
8
H
9
H
p
p
p
H
p
p
9
p
29
p
9
L
10
»
L
L
L
H
p
p
10
P
30
p
10
M
11
H
P
P
P
H
H
H
11
P
31
P
11
H
12
L
P
P
P
H
P
P
1 2
P
32
P
12
H
13
H
P
P
P
H
L
P
13
P
33
P
13
P
14
H
P
P
P
H
H
P
14
P
34
P
14
H
15
*
P
P
L
P
H
15
P
35
*
16
H
P
P
P
H
H
16
P
36
*
1 "7
D
r
D
r
L
1 /
r
31
□
r
18
P
P
P
18
P
38
H
19
L
P
L
19
P
39
P
z u
U
n
u
n
n
1
L
u
n
PIN
IC
IC
IC
IC
IC
PI N
IC
PI N
IC
PIN
IC
PIN
IC
NO.
UC10
UC12
UD1
UD3
UE1
NO.
UE4
NO.
UE4
NO.
UE5
NO.
UE5
1
p
»
p
p
p
1
L
21
P
1
L
21
P
2
H
L
p
P
P
2
P
22
L
2
L
22
P
3
H
L
P
P
P
3
P
23
P
3
P
23
P
4
H
H
P
P
L
4
P
24
P
4
P
24
P
5
H
p
p
p
p
5
p
25
H
5
p
25
p
6
H
•
P
P
P
6
P
26
P
6
H
26
P
7
H
H
H
P
L
7
P
27
P
7
L
27
P
8
H
L
P
P
H
8
P
28
P
8
L
28
H
9
H
P
H
p
p
9
p
29
p
9
p
29
p
10
H
P
L
L
H
10
p
30
p
10
L
30
P
11
H
P
L
P
P
11
P
31
P
11
L
31
L
12
L
H
P
P
P
12
P
32
P
12
H
32
L
13
H
H
P
P
L
13
P
33
P
13
H
33
P
14
H
H
P
P
H
14
P
34
P
14
P
34
P
15
H
H
P
P
15
H
35
P
15
H
35
P
16
H
H
P
P
16
H
36
P
16
36
P
17
H
p
p
17
H
37
p
17
p
37
H
18
P
P
P
18
P
38
P
18
P
38
P
19
P
P
P
19
H
39
P
19
P
39
P
20
P
H
H
20
P
40
P
20
P
40
P
21
P
22
P
23
P
24
H
NOTE: Logic probe readings taken in Power Up mode, with-
out Disk II Interface Board inserted, no keys press-
ed unless otherwise noted.
Logic Probe Display
L = Low
H = High
P= Pulse
# = Open (No light On)
(1) Probe indicates L when CONTROL key is pressed.
(2) Probe indicates L when SHIFT key is pressed.
(3) Probe indicates H when any key is pressed except the
CONTROL, SHIFT, CAPS LOCK, RESET and APPLE
keys.
(4) Probe indicates P when any key is pressed except the
CONTROL, SHIFT, CAPS LOCK, RESET and APPLE
keys.
(5) Probe indicates H when CAPS LOCK key is up.
(6) Readings taken after pressing SPACE bar.
27
LOGIC CHART (Continued)
MAIN BOARD LOGIC (Continued)
PI N
IC
PI N
IC
PI N
IC
PI N
IC
PI N
IC
PI N
IC
PI N
IC
PI N
IC
NO.
UE8
NO.
UE8
NO.
UE10
NO.
UE10
NO.
UE1 2
NO.
UE12
NO.
UE14
NO.
UE14
1
H
15
P
1
H
15
P
1
L(6)
13
P
1
P
21
L
2
P
16
P
2
P
16
P
2
L(6)
14
P
2
P
22
L
3
P
17
P
3
P
17
P
3
L(6>
15
P
3
P
23
L
4
P
18
P
4
P
18
P
4
H(6)
16
P
4
L
24
L
5
P
19
P
5
P
19
P
5
L(6)
17
H
5
L(3)
25
L
6
P
20
L
6
P
20
L
6
L(6)
18
L
6
L(6)
26
L
7
P
21
P
7
P
21
P
7
H(6)
19
L
7
L(6)
27
L
8
P
22
P
8
P
22
H
8
H(6)
20
P
8-
H(6)
28
H(1 )
9
P
23
P
9
P
23
P
9
P
21
H
9
L(6)
29
H(2)
10
P
24
P
10
P
24
P
10
P
22
L(5)
10
L(6)
30
H
1 1
P
25
P
1 1
P
25
P
1 1
P
23
H(6)
1 1
L(6)
31
L
12
P
26
H
12
P
26
H
12
L
24
H
12
H(6)
32
P
13
P
27
H
13
P
27
H
13
H(6)
33
P
14
L
28
H
14
L
28
H
14
H(6)
34
P
15
L
35
p
16
L(4)
36
P
17
L
37
P
18
L
38
P
19
L
39
P
20
L
40
P
PI N
IC
PI N
IC
PI N
IC
IC
IC
IC
IC
IC
IC
IC
IC
NO.
UF4
NO.
UF4
NO.
UF5
UF6
UF7
UF8
UF9
UF10
UF11
UF12
UF13
1
P
13
P
1
P
H
H
H
H
H
H
H
H
2
P
14
P
2
P
P
P
P
P
P
P
P
P
3
P
15
P
3
P
P
P
P
P
P
P
P
P
4
P
16
P
4
P
P
P
P
P
P
P
P
P
5
P
17
p
5
p
P
P
P
P
P
P
P
P
6
P
18
L
6
P
P
P
P
P
P
P
P
P
7
P
19
P
7
P
P
P
P
P
P
P
P
P
8
P
20
P
8
L
H
H
H
H
H
H
H
H
9
P
21
L
9
H
P
p
p
p
P
p
p
p
10
P
22
P
10
P
P
P
P
P
P
P
P
P
1 1
P
r
D
r
1 1
P
r
D
r
P
r
P
r
P
r
P
r
P
r
P
r
P
r
12
L
24
H
12
p
p
p
p
p
p
p
p
p
13
p
p
p
p
p
p
p
p
p
14
p
p
p
p
p
p
p
p
p
15
p
p
p
p
p
p
p
p
p
16
H
L
L
L
L
L
L
L
L
NOTE: Logic probe readings taken in Power Up mode, with-
out Disk II Interface Board inserted, no keys press-
ed unless otherwise noted.
Logic Probe Display
L = Low
1-1 = High
P = Pulse
* = Open (No light On)
(1) Probe indicates L when CONTROL key is pressed.
(2) Probe indicates L when SHIFT key is pressed.
(3) Probe indicates H when any key is pressed except the
CONTROL, SHIFT, CAPS LOCK, RESET and APPLE
keys.
(4) Probe indicates P when any key is pressed except the
CONTROL, SHIFT, CAPS LOCK, RESET and APPLE
keys.
(5) Probe indicates H when CAPS LOCK key is up.
(6) Readings taken after pressing SPACE bar.
28
LOGIC CHART (Continued)
DISK II INTERFACE BOARD LOGIC
PI N
NO.
IC
UA2
IC
UA3
IC
UB2
IC
UB3
IC
UC2
IC
UC3
IC
UD2
IC
UD3
1
P
H
L
P
P
P
L
P
2
H
P
H
P
P
P
H
P
3
P
P
P
P
P
P
H
P
4
H
P
H
P
L
P
H
P
5
L
P
P
P
L
P
L
P
6
H
P
L
P
L
P
H
P
7
L
P
L
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L
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L
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8
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L
P
P
L
P
L
P
9
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10
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L
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11
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12
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13
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15
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18
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19
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NOTE: Logic probe readings taken while running the fol-
lowing program.
10 D$ = CHR$(4)
20 PRINT D$; "OPEN SAMS"
30 PRINT D$; "WRITE SAMS"
40 FOR X = 1 TO 50
50 PRINT "THIS IS A TEST"
60 NEXT X
70 PRINT D$; "CLOSE"
80 GOTO 20
Logic Probe Display
L= Low
H = High
P = Pulse
# = Open (No light On)
29
SAFETY PRECAUTIONS
1. Use an isolation transformer for servicing.
2. Maintain AC line voltage at rated input.
3. Remove power from the Computer before servicing or installing electrostatically sensitive devices. Examples of typical
ES devices are integrated circuits and semiconductor "chip" components.
4. Use extreme caution when handling the printed circuit boards. Some semiconductor devices can be damaged easily by
static electricity. Drain off any electrostatic charge on your body by touching a known earth ground. Wear a commercial-
ly available discharging wrist strap device. This should be removed prior to applying power to the unit under test.
5. Use a grounded-tip, low voltage soldering iron.
6. Use an isolation (times 10) probe on scope.
7. Do not remove or install boards, floppy disk drives, printers, or other peripherals with power On.
8. Do not use freon-propelled sprays. These can generate electrical charges sufficient to damage semiconductor devices.
9. The Computer cabinet is equipped with vents to prevent heat build-up. Never block, cover, or obstruct these vents.
10. Instructions should be given, especially to children, that objects should not be dropped or pushed into the vents of the
cabinet. This could cause shock or equipment damage.
11. Never expose the Computer to water. If exposed to water, turn the unit Off. Do not place the Computer near possible
water sources.
12. Never leave the Computer unattended or plugged into the AC outlet for long periods of time. Remove AC plug from AC
outlet during lightning storms.
13. Never use liquids or aerosols directly on the Computer. Spray on cloth and then apply to the Computer cabinet. Make
sure the Computer is disconnected from the power line.
SCHEMATIC NOTES
— «— Circuitry not used in some versions
Circuitry used in some versions
e See parts list
* Ground
rrtrt Chassis
Waveforms and voltages taken from ground, unless noted
otherwise
Voltages, Waveforms and Logic Probe readings for main
board taken with Computer in Power Up mode, no keys
pressed, unless otherwise noted.
Voltages, Waveforms and Logic Probe readings for disk II
interface board taken while running the following Basic
program.
10 DS = CHR$(4)
20 PRINT D$; "OPEN SAMS"
30 PRINT D$; "WRITE SAMS"
40 FOR X = 1 TO 50
50 PRINT "THIS IS A TEST"
60 NEXT X
70 PRINT D$; "CLOSE"
80 GOTO 20
Waveforms taken with triggered scope and Sweep/Time
switch in Calibrate position, scope input set for DC
coupling on reference voltage waveforms. Switch to AC
input to view waveforms after DC reference is measured
when necessary. Each waveform is 7 cm. width with DC
reference voltage given at the bottom line of each wave-
form.
Time in /*sec. per cm, given with p-p reading at the end of
each waveform.
Item numbers in rectangles appear in the alignment/ad-
justment instructions.
Supply voltages maintained as shown at input.
Voltages measured with digital meter, no signal.
Controls adjusted for normal operation.
Terminal identification may not be found on unit.
Capacitors are 50 volts or less, 5% unless noted.
Electrolytic capacitors are 50 volts or less, 20% unless
noted.
Resistors are VzW or less, 5% unless noted.
Value in ( ) used in some versions.
Measurements with switching as shown, unless noted.
Logic Probe Display
L= Low
H = High
P = Pulse
* = Open (No light On)
(1) Probe indicates L when CONTROL Key is pressed.
(2) Probe indicates L when SHIFT key is pressed.
(3) Probe indicates H when any key is pressed except the
CONTROL, SHIFT, CAPS LOCK, RESET and APPLE
keys.
(4) Probe indicates P when any key is pressed except the
CONTROL, SHIFT, CAPS LOCK, RESET and APPLE
keys.
(5) Probe indicates H when CAPS LOCK key is up.
(6) Readings taken after pressing SPACE bar.
(7) Logic readings not taken.
30
ahtk LINE DEFINITIONS *
Address Lines Q3 General Purpose Clock
A * u Acknowledge RAO Thru RA7, RA9, RA10
ALTVID RDY. . . Rpadu
ANO Thru AN3 RESET .. . . . tt\
™tf" n „ Cassette Enable READ DATA Read Data
Capital (Letter) Lock ROMEN1, ROMEN2 ROM Enable Lines
CLKEN Clock Enable R/W Read/Write
° M "? ATE ■ Ciei " R/W80 Read/Write 80 Character
CNTL Control SEGA
COXX SEGB
C06X.C07X SEROUT Serial Output
CXXX SHFT Shift
DMA Direct Memory Access SPKR SDeaker
DO Thru D7 Data Lines STB Stro be
DEV1 Thru DEV7 Peripheral Device Select SW0/OAPL
cm A nn E1 ' ENABLE2 Enable SW1/CAPL Switch Capital
ENKBD Enable Keyboard SW2
ENTMG SYNC Sync
ENVID Enable Video VC
EN80 Enable 80 Character Width VIDO Thru VID7
FRCTXT V|D7M
2 Graphics WNDW Window
Hu Horizontal WRITE DATA Write Data
l/OSTROBE Input/Output Strobe WRITE PROTECT Write Protect
\"" WRITE REQ Write Request
IOSEL Input/Output Select X0 Thru X7
IRQ Input Request Y0 Thru Y9
k^trr Keyboard 3.58M 3.58MHz
KSTRB 7M 7MHz
LDPS Load Parallel to Serial 14M 14MHz
SSSSf 0f Buffered Data Lines 80VID '.'.'.'.'.'.'.■.■.V.80Character Video
MD "N/OUT Buffered Data Input/Output /xPSYNC
"° T0R0N Motor On O0 Phase 2
" R „ Mem °^ Read 01 Phase One O >
NMI Non-Maskable Interrupt OA Phase A ° 2
PDLOThru PDL3 Game Paddle Lines OB [[Z" P Tall B F ?
0C Phase C= m
KHAi> OD Phase D
Any Bar above any alphabetical or numerical combination indicates line level in a low (0) state.
31
IC PINOUTS & T
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© Howard W. S»ms & Co.. Inc. 1985
SEE SCHEMATIC NOTES BEFORE
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DISK II INTERFACE BOARD
33
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A PHOTOPACT STANDARD NOTATION SCHEMATIC
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© Howard W. Sams & Co. 1985 POWER SUPPLY
34
A PHOTOFACT STA NDARD NOTATION SCHEMATIC
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© Howard W Sams & Co 1985
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